repeating a year?

some things you should know:
-I go to a private school (lets call it school A; its a small school, not the big rich kind, its got about 80-100 people and we have k-12th)
-our high school program is 3 years, they did this because you only need 3 credits for every core subject except English and it’s easier to study English over the summer (so you have no choice but to skip a grade, which I was not a supporter of)
-it’s a pretty flexible school (anything goes, even though I wish i could start over at a public school)

my situation:
-I studied freshman year at school (the core courses I took were physical science, geometry, american history, English 9)
-the summer after, I took English 10 (which counted as “skipping a grade”, so basically that summer was my sophmore year)
-I just finished my junior year (I took chemistry, algebra 2, world history, english 11)
-this summer I’m taking pre-calculus and biology
-Next year for my senior year I’m taking AP calculus, AP language and composition, AP biology, and AP government (got a pretty full year)
-I started to think of going to a different school (lets call it school B) for another year after I’m done with school A, so i would get the chance to do more classes like trig. and more electives

so my question is if going to school B after I’m done with school A be counted as my senior year, or i would be repeating my senior year? (and if it is like repeating than I don’t think I would do another year). Or does studying english 10 not count as my sophomore year, and could i go to school B for another year and it would look like i did 4 years? and I wanted to know if either way I did it, would it affect my chances of getting into a good college/university?

I’m not sure what counts as a full year of school at School A, but if you have the chance to take more APs/electives and improve either your GPA or the rigor of your schedule at School B, I would go for it!